Design of Cyclodextrin/Aptamer-Based Dual Recognition Fluorescent Sensor for Sensitive Detection of Galectin-3

Early detection of Heart Failure (HF) is crucial for enhancing patient outcomes, and recent developments in noninvasive biomarker sensors have enabled monitoring at the early stages to achieve this goal. In this study, we developed an HF detection platform targeting the biomarker Galectin-3 (Gal3), utilizing two specific binding sites: β hexakis-(6-mercapto-6- deoxy)-β-cyclodextrin (mCD) and an aptamer binding site.
Computational methods, such as molecular docking, were employed to select and design an aptamer with enhanced binding affinity for Gal3. The engineered aptamer, Apt4_C15A, demonstrated strong binding affinity to Gal3, as confirmed through fluorescence assays, with a low equilibrium dissociation constant (KD) of 3.20 ± 1.25 μM. The sensor was constructed as a sandwich platform, with mCD functionalized on silver-coated plates serving as the primary capture molecule and a 6- carboxyfluorescein amidite (FAM)-tagged aptamer serving as both the secondary capture molecule and fluorescent signal probe. The sensor exhibited high sensitivity, achieving a detection limit of 11.03 ng/mL within a linear range of 10–200 ng/mL, effectively covering clinically relevant Gal3 concentrations. This innovative mCD/aptamer-based fluorescent sensor demonstrated excellent detection performance, underscoring its potential as a reliable platform for early HF biomarker detection. Future improvements will focus on optimizing sensor fabrication conditions to minimize
non-specific binding, further enhancing sensor accuracy and robustness.